AdventureQuest Worlds is an online browser-based MMORPG created in 2008 by Artix Entertainment and is still updated on a weekly basis.
The main saga, also known as the "13 Lord of Chaos Saga", revolves around The Hero on the middle of a war between Good and Evil. During a fight between the leader of both sides, an unexpected side, Chaos, joins the fight and ends up killing the leader of the Evil Faction, Sepulchure, so his daughter, Gravelyn becomes the new Empress of Evil. At the end of this, The Hero must pick a side and make his way towards the objective of defeating a major threat: Drakath, the Chaos Champion. The Hero must defeat all of the 13 Lord of Chaos in order to defeat Drakath.